1. Field of the Invention
This invention relates in general to a cell constructed in CMOS technology for forming at least one resistor and/or at least one capacitor wherein at least one p-channel transistor and at least one n-channel transistor are provided which can be particularly used in a gate array.
2. Description of the Prior Art
For the rapid construction of customer specified modules, it is known to use modules constructed from premanufactured or predeveloped cells in which the individual cells are connected to each other according to the customers requirements. One possibility consists in the use of so-called gate arrays in which pairs of transistors constructed in CMOS technology are arranged in the form of a matrix on a module. Gate arrays of this kind are described, for example, in "Elektronik" Volume 19 of Oct. 21, 1984, Page 68 or in "VLSI-Design" of February 1984, Pages 78 through 80.
It is sometimes desirable from the circuit standpoint in known CMOS gate arrays to provide surface space saving resistors. However, none of the prior art provides such resistors in the region of the cells. Resistors are used, for example, in fixing determinant levels on signal lines, in store write and read lines and in the wiring of delay components. It also would be desirable to have available capacitors of a surface space saving design for the construction of dynamic storage cells and delay components. It should be borne in mind that the active zones on a CMOS gate array have a predetermined structure. Only the non-customs specific gates and diffusion zones of the basic cells can be used for the capacitors and the resistors. Particularly, for high ohmic resistors and high value capacitors which are large as compared to a typical gate capacitor, it is necessary to use a relatively large number of the basic cells of the gate array to obtain the desirable values.
The construction of resistors and capacitors using the diffusion zones and gates already available on the gate array has the disadvantage that a relatively large percentage of the basic cells must be used for this purpose.